The present invention relates to the generation of microwave electromagnetic radiation.
Sources of directional microwave electromagnetic radiation, and especially steerable sources of such radiation may be used, e.g., in communications and radar; in the former case, a directional beam may be steered for line-of-sight alignment, and in the latter, for rapid sweeping of a spatial angle. For these and similar applications, microwave electromagnetic radiation preferably has a frequency greater than approximately 3 gigahertz (i.e., a wavelength of less than 10 cm).
For the generation of such radiation, a variety of devices have been devised, with representative disclosures as follows:
U.S. Pat. No. 3,899,428, issued Aug. 12, 1975 to D. H. Auston et al., disclosing a transducer of electro-magnetic radiation comprising an electrically polarizable, typically pyroelectric medium; PA1 U.S. Pat. No. 4,329,686, issued May 11, 1982 to G. Mourou, disclosing the generation of microwave pulses by means of a laser-activated semiconductor switch in a waveguide cavity; PA1 U.S. Pat. No. 4,636,794, issued Jan. 13, 1987 to V.P. McGinn, disclosing a steerable microwave radiator antenna including a plurality of elements having directional radiation patterns, with directional characteristics resulting from superposition of radiation from optically controlled radiator elements; PA1 U.S. Pat. No. 4,684,952, issued Jan. No. 13, 1987 to R. E. Munson et al., disclosing a (passive) microwave reflector or "reflectarray" including microstrip antenna elements which may be formed by photolithographic processing of a metal layer on a dielectric substrate; PA1 U.S. Pat. No. 4,739,334, issued Apr. 19, 1988 to R. A. Soref, disclosing a phased-array antenna including a plurality of radiator elements producing phase-shifted radio signals in response to phase-shifted optical signals; PA1 U.S. Pat. No. 4,751,513, issued Jun. 14, 1988 to A. S. Daryoush et al., disclosing a microwave radiator antenna, with tuning of frequency response by means of a photosensitive element connected to a radiator element; PA1 U.S. Pat. No. 4,855,749, issued Aug. 8, 1989 to A. P. DeFonzo, disclosing a planar opto-electronic transducer including tapered slot-line antenna elements which are monolithically integrated on a silicon-on-sapphire substrate; and PA1 U.S. Pat. No. 4,864,312, issued Sep. 5, 1989 to J. P. Huignard et al., disclosing a microwave radiator antenna with beam scanning controlled by electro-optical modulators which define optical paths having different lengths.
In the field of such disclosures, namely of microwave electromagnetic radiation sources, the invention described in the following provides for a particularly advantageous and readily manufacturable device structure for producing and controlling the direction of collimated beams of microwave electromagnetic radiation pulses.